Observation of two charged bottomonium-like resonances in Y(5S) decays.

Abstract

WereporttheobservationoftwonarrowstructuresinthemassspectraoftheðnSÞ(n¼1,2,3) andhb ðmPÞ(m¼1,2)pairsthatareproducedinassociationwithasinglechargedpioninð5SÞ decays.Themeasuredmassesandwidthsofthetwostructuresaveragedoverthefivefinalstatesare M1 ¼ð10607:22:0ÞMeV=c2,1 ¼ð18:42:4ÞMeV,andM2 ¼ð10652:21:5ÞMeV=c2,2 ¼ ð11:52:2ÞMeV.Theresultsareobtainedwitha121:4fb1datasamplecollectedwiththeBelle detectorinthevicinityoftheð5SÞresonanceattheKEKBasymmetric-energyeþecollider.